British health officials are carrying out blood tests on a man who may have contracted foot-and-mouth disease.
North Cumbria Health Authority said the man, an abattoir worker who has not been identified, was being investigated for "possible foot-and-mouth disease," although they added that his condition "is giving no cause for concern".
If the case is confirmed it will be another blow to the rural community and to the tourist industry in Britain and Ireland, engaged in a battle to convince tourists that they can visit safely.
The Ministry of Health insisted the case had not been confirmed and refused to speculate on how the man, who was involved in the slaughtering and disposal of carcasses in north Cumbria, may have been infected with the disease.
"It was certainly not airborne," a spokesman said, adding that if the first case of human foot-and-mouth since 1966 was confirmed, it had arisen from "prolonged and very specific" contact with infected animals.
The results of the blood tests will not be known for about two days but it is understood that the man is showing symptoms of the disease, including blisters in the mouth. In humans, foot-and-mouth is not a life-threatening condition and it cannot be transmitted between humans.
Responding to the suspected case, the National Farmers' Union said it was "very concerned".
As health officials investigated the suspected case, ministers admitted there was no risk-free method of disposing of carcasses, as opposition grew against the burning of animals on large pyres.
Members of the rural community living close to large pyres, some of which have been burning carcasses for several weeks, have expressed concerns about the risk to public health by the amount of dioxins released by the fires.
In the House of Commons, the Environment Minister, Mr Michael Meacher, acknowledged public concerns when he told MPs that there was no riskfree option, but he said leaving carcasses rotting in fields for several weeks was "the worst option of all".
As part of the effort to clear the backlog of carcasses awaiting disposal in Devon, the Defence Secretary, Mr Geoff Hoon, announced that extra troops would be sent to the area.
A mass burial site is being prepared at Ash Moor in Devon but it will not be ready for several days.